I see a few registrars allowing per-registrations, but can't find any dates for Sunrise, early access, GA, or any other information. Apparently the registry is Dish DBS Corporation, but that's not useful either.
The only authoritative source on this is ICANN/IANA (and despite its name "icannwiki.org" is not run by ICANN so should not be taken as authoritative source)
Specifically you can go to the following addresses:
If you do a search for DATA on first URL you see 3 applicants.
If you go to second URL you can see that it was in a contention status because of 3 applicants for it, and that was resolved: the "Dish DBS Corporation" case has prevailed on the other ones.
So if you go again to first URL you can see details about this application and it says: "Application status: Delegated" which is also seen on https://www.iana.org/domains/root/db/data.html which is authoritative.
Record last updated 2017-07-20. Registration date 2016-12-15.
This TLD exists in the root zone since a long time but does not seen open to registrations.
You need to go back reading its application. While things can change after it, it says:
Applicant seeks the proposed .DATA gTLD as a controlled gTLD, to serve as a trusted and intuitive namespace to:
• encourage Members (as defined below) to create a connected digital presence and personalized .DATA experience for their customers, partners and others. Applicant will further the creation of such a connected digital presence by providing Members with open and non-discriminatory access for Members to the .DATA gTLD, in accordance with the Registry Agreement and ICANN rules and guidance;
• support secure interaction and communication with individuals and entities with whom any .DATA Registrants (as defined below), have or may have a business relationship;
• encourage .DATA Registrants to simplify Internet user navigation to information about the .DATA Registrants’ products and services;
• demonstrate market leadership by providing a secure Registry by which .DATA Registrants can implement policies and procedures which protect their customers privacy and confidential information online; and
• enhance the communications ability of .DATA Registrants in the use and deployment of this new gTLD registry.
As used herein, the term “Affiliates” means DISH Network Corporation and its direct and indirect subsidiaries, other than Applicant. As used herein, the term “Qualified Applicants” shall mean entities that provide video streaming or consumer content storage services, products and vendors. As used herein, the term “Members” means Applicant, Affiliates of Applicant, Qualified Applicants. For the avoidance of doubt, Applicant reserves the right to open this TLD to additional classes of registrants in the future (“Other Registrants”), which Other Registrants shall not be considered Members.
Said differently: this TLD is not planned to be open to the general public.
You can find articles online about it: http://domainincite.com/19239-another-new-gtld-goes-to-a-closed-generic-applicant
Dish DBS has won the contention set for the .data gTLD, even though its proposed business model has been banned by ICANN.
It’s the second string this week to go to a “closed generic” applicant, that wants to keep all the domains in the TLD to itself even though it’s not a dot-brand.
As withdrawal now seems to be off the cards, it seem that .data will not see the light of day for some time to come.
If anything changes, for sunrise/GA/etc. the authoritative source is: https://newgtlds.icann.org/en/program-status/sunrise-claims-periods
When a registry starts and opens to the public it has to give data on dates, and this will be reflected at that URL.
Besides, a knowledgeable registrar should be able to guide you and basically tell you all the above.
On pre-registrations, it is a bad idea in general, specifically before knowing if the TLD is planned to be open, and what are the eligibility rules. You can find ICANN own recommemdations on that at https://www.icann.org/news/blog/pre-reserve-a-domain-name-or-not-icann-answers-the-question
As responsible Registrars are advising, successful pre-registration of a domain cannot be guaranteed. ICANN seconds that advice, cautioning that registrants should be wary of anyone who claims to be able to guarantee a domain registration on a new gTLD.
While we caution potential registrants to be skeptical of claims that a name can be “guaranteed” names, ICANN supports programs that are set up to help interested parties keep track of when the new domain names will be available. For example, some Registrars are providing programs that allow potential registrants to subscribe to status updates on new gTLDs.
Note the distinction between "pre-registration" as in "paying in advance to have a guaranteed or not future right" and "subscribing to get notifications about changes on a TLD".
I don't think the future registry has been appointed yet. Apparently you still have 3 applicants and it hasn't been decided who will own .DATA in the end.
Also there seems to be a "warning" on the Dish application because of anti-trust/anti-competition issues.
Source : https://icannwiki.org/.data
What's for sure : don't expect it in 2019...